Yoshiaki Tsunawaki

An adiabatic transition field in a solenoid-induced helical wiggler has been successfully generated using staggered Ni plates with different thicknesses of 6 to 0.1 mm. However, trials using Fe plates instead of Ni plates failed to generate a suitable adiabatic transition field To elucidate these phenomena, the magnetic behavior of Ni and Fe plates with regard to the thickness dependence was studied by a fundamental electromagnetic calculation with the aid of a field calculation based on the finite element method The magnetic flux density of a Ni plate increases and then decreases with the reduction in thickness from 6 to 0.8 mm and from 0 8 to 0 1 mm, respectively On the other hand. the magnetic flux density of an Fe plate does not have a maximum but monotonically increases until the smallest thickness of 0.1 mm. The dependence of magnetic flux density on thickness differs between Ni and Fe plates This difference explains the necessity of using a Ni plate for the adiabatic transition part of the wiggler. Furthermore, we estimated three types of demagnetizing factor depending on the thickness of the plate. (C) 2009 The Japan Society of Applied Physics

An adiabatic transition field in a solenoid-induced helical wiggler has been successfully generated using staggered Ni plates with different thicknesses of 6 to 0.1 mm. However, trials using Fe plates instead of Ni plates failed to generate a suitable adiabatic transition field To elucidate these phenomena, the magnetic behavior of Ni and Fe plates with regard to the thickness dependence was studied by a fundamental electromagnetic calculation with the aid of a field calculation based on the finite element method The magnetic flux density of a Ni plate increases and then decreases with the reduction in thickness from 6 to 0.8 mm and from 0 8 to 0 1 mm, respectively On the other hand. the magnetic flux density of an Fe plate does not have a maximum but monotonically increases until the smallest thickness of 0.1 mm. The dependence of magnetic flux density on thickness differs between Ni and Fe plates This difference explains the necessity of using a Ni plate for the adiabatic transition part of the wiggler. Furthermore, we estimated three types of demagnetizing factor depending on the thickness of the plate. (C) 2009 The Japan Society of Applied Physics

beta-tricalcium bis(orthophosphate) [Ca-3(PO4)(2)] (beta-TCP) was mechanochemically treated with a mortar grinder in three different atmospheres of air, wet N-2, and wet CO2. H2O and CO32- were incorporated into ground beta-TCP, the amount of which depended on both the grinding time and the atmosphere. As the grinding time of beta-TCP increased, it hydrolyzed easily to Ca-deficient hydroxyapatite. The apatite-formation ratio for beta-TCP ground in Wet CO2 was remarkably lower than that for beta-TCP ground in air or wet N-2. The role of H2O and CO32- in the hydrolysis of ground beta-TCP was investigated by calorimetry together with spectroscopy. In calorimetry for each ground beta-TCP, a strong exothermic band was observed, which was followed by a broad exothermic band. It is considered that the first band corresponds to the process of adsorption of H2O in the solvent onto the fresh surface of ground beta-TCP and the second broad band corresponds to the apatite-formation process. With increasing amount of H2O incorporated into ground beta-TCP, both the heat evolution of the first exothermic band and the apatite-formation ratio increased linearly. The H2O incorporated into ground,beta-TCP promotes the dissolution of beta-TCP and apatite formation. In terms of the effect of the incorporated CO32- on hydrolysis, the incorporated CO32- prevents not only apatite formation but also the dissolution of beta-TCP. (C)2009 The Ceramic Society of Japan. All rights reserved.

Formation of the metal particles of Cd has been studied by nanosecond laser flash photolysis using an ArF excimer laser with the oscillation wavelength of 193 nm. The sample was a 10% methanol solution of CdCl(2). The solvated electron, e(aq)(-), was generated by the excitation of charge transfer bands of Cl(-) to solvent. The ea(aq)(-) efficiently reduced Cd(2+) to Cd(+) during a laser pulse of 30 ns (FWHM). The Cd particles were produced by the reaction between Cd(+) and Cd(+). In the air saturated solution, the Cd(+) was easily oxidized by dissolved oxygen. The concentration of the Cd particles formed in the degassed solution was approximately twice of that in the air saturated solution. Crown Copyright (c) 2008 Published by Elsevier B.V. All rights reserved.

A compact electron gun using field emitter array has been developed. With a simple triode configuration consisting of FEA, mid-electrode and anode electrode, the electron gun produces a parallel beam with a diameter of 0.5 mm. This electron gun is applicable for compact radiation sources such as Cherenkov free-electron lasers. (c) 2008 Elsevier B.V. All rights reserved.

Octacalcium bis (hydrogenphosphate) tetrakis (orthophosphate) pentahydrate [Ca(8)(HPO(4))(2)(PO(4))(4)center dot 5H(2)O] (OCP) consists of so-called "apatite" layers and "hydrate" layers. We have researched on the synthesis of layered OCP including various kinds of carboxylate ions. Calcium hydrogen phosphate dihydrate [CaHPO(4)center dot 2H(2)O] (DCPD) and alpha-tricalcium bis (orthophosphate) [Ca(3)(PO(4))(2)] (alpha-TCP) were mixed with respective carboxylic acid such as succinic acid, glutamic acid, aspartic acid, and citric acid which are bioactive organic compounds. The mixture was hydrolyzed to OCP including carboxylate ions after reaction for 24 h at 40-60 degrees C. We found that the OCP including bioactive organic compound is easily formed under the presence of carboxylic acid without any control of pH. It was observed that the synthesized products consisted of small sized thin layers. Thermolysis of OCPs including carboxylate ions did not show significant change in the structure at lower temperature than 400 degrees C. At 600 degrees C, they decomposed into hydroxyapatite [Ca(10)(PO(4))(6)(OH)(2)] (HAp) and beta-TCP together with a small amount of beta-dicalcium diphosphate [beta-Ca(2)P(2)O(7)]. The respective amount of their reformed products depended on the content and the species of carboxylate ions incorporated into OCP. (C) 2008 Elsevier B.V. All rights reserved.

Formation of the metal particles of Cd has been studied by nanosecond laser flash photolysis using an ArF excimer laser with the oscillation wavelength of 193 nm. The sample was a 10% methanol solution of CdCl(2). The solvated electron, e(aq)(-), was generated by the excitation of charge transfer bands of Cl(-) to solvent. The ea(aq)(-) efficiently reduced Cd(2+) to Cd(+) during a laser pulse of 30 ns (FWHM). The Cd particles were produced by the reaction between Cd(+) and Cd(+). In the air saturated solution, the Cd(+) was easily oxidized by dissolved oxygen. The concentration of the Cd particles formed in the degassed solution was approximately twice of that in the air saturated solution. Crown Copyright (c) 2008 Published by Elsevier B.V. All rights reserved.

A compact electron gun using field emitter array has been developed. With a simple triode configuration consisting of FEA, mid-electrode and anode electrode, the electron gun produces a parallel beam with a diameter of 0.5 mm. This electron gun is applicable for compact radiation sources such as Cherenkov free-electron lasers. (c) 2008 Elsevier B.V. All rights reserved.

Octacalcium bis (hydrogenphosphate) tetrakis (orthophosphate) pentahydrate [Ca(8)(HPO(4))(2)(PO(4))(4)center dot 5H(2)O] (OCP) consists of so-called "apatite" layers and "hydrate" layers. We have researched on the synthesis of layered OCP including various kinds of carboxylate ions. Calcium hydrogen phosphate dihydrate [CaHPO(4)center dot 2H(2)O] (DCPD) and alpha-tricalcium bis (orthophosphate) [Ca(3)(PO(4))(2)] (alpha-TCP) were mixed with respective carboxylic acid such as succinic acid, glutamic acid, aspartic acid, and citric acid which are bioactive organic compounds. The mixture was hydrolyzed to OCP including carboxylate ions after reaction for 24 h at 40-60 degrees C. We found that the OCP including bioactive organic compound is easily formed under the presence of carboxylic acid without any control of pH. It was observed that the synthesized products consisted of small sized thin layers. Thermolysis of OCPs including carboxylate ions did not show significant change in the structure at lower temperature than 400 degrees C. At 600 degrees C, they decomposed into hydroxyapatite [Ca(10)(PO(4))(6)(OH)(2)] (HAp) and beta-TCP together with a small amount of beta-dicalcium diphosphate [beta-Ca(2)P(2)O(7)]. The respective amount of their reformed products depended on the content and the species of carboxylate ions incorporated into OCP. (C) 2008 Elsevier B.V. All rights reserved.

Photochemistry of hexafluoroacetylacetone has been studied by photoproduct analysis using infrared spectroscopy. Hexafluor-oacetylacetone was irradiated by KrF excimer laser with the oscillation wavelength of 248 nm during 100 s and the photoproducts were analyzed by transmittance measurement of FT-IR in the spectral region between 3500 and 1300 cm(-1). One of the photoproducts was CO. It was estimated that the formation efficiency of CO was approximately 0.6. (c) 2007 Elsevier Ltd. All rights reserved.

Photochemistry of hexafluoroacetylacetone has been studied by photoproduct analysis using infrared spectroscopy. Hexafluor-oacetylacetone was irradiated by KrF excimer laser with the oscillation wavelength of 248 nm during 100 s and the photoproducts were analyzed by transmittance measurement of FT-IR in the spectral region between 3500 and 1300 cm(-1). One of the photoproducts was CO. It was estimated that the formation efficiency of CO was approximately 0.6. (c) 2007 Elsevier Ltd. All rights reserved.

Synthesis of single-wall carbon nanotubes (SWNTs) was carried out by an ablation method using a XeCl excimer laser. It was irradiated onto a graphite target containing Co and Ni at the temperatures of 1073, 1173, 1273, 1373, 1473, 1523 and 1623 K under the atmosphere (0.1 MPa) of Ar gas with the flow rate of 12 ml/min. The measurement by a scanning/transmission electron microscope and Raman spectroscopy found the formation of SWNTs with the diameter of about 1.3 nm and the length of about 2 mu m in ablated carbonaceous soot. The ratio of peak intensity of 1590 cm(-1) (G band) to that of 1335 cm(-1) (D band) in the high frequency Raman spectra increased with increasing the ambient temperature. The radial breathing mode (RBM) in the low frequency Raman spectra shows that the mean diameter of SWNTs increased with increasing the ambient temperature. (C) 2007 Elsevier B.V. All rights reserved.

Synthesis of single-wall carbon nanotubes (SWNTs) was carried out by an ablation method using a XeCl excimer laser. It was irradiated onto a graphite target containing Co and Ni at the temperatures of 1073, 1173, 1273, 1373, 1473, 1523 and 1623 K under the atmosphere (0.1 MPa) of Ar gas with the flow rate of 12 ml/min. The measurement by a scanning/transmission electron microscope and Raman spectroscopy found the formation of SWNTs with the diameter of about 1.3 nm and the length of about 2 mu m in ablated carbonaceous soot. The ratio of peak intensity of 1590 cm(-1) (G band) to that of 1335 cm(-1) (D band) in the high frequency Raman spectra increased with increasing the ambient temperature. The radial breathing mode (RBM) in the low frequency Raman spectra shows that the mean diameter of SWNTs increased with increasing the ambient temperature. (C) 2007 Elsevier B.V. All rights reserved.

Chemical actinometer for UV laser nanoprocessing has been developed using infrared spectroscopy for the photoproduct of UV irradiated acetylacetone. Sample was hexafluoroacetylacetone, HFA, in which the H atoms of two methyl groups of acetylacetone are replaced by F atoms. It was irradiated by a KrF excimer laser with the oscillation wavelength of 248 nm during 100 seconds and the photoproducts were analyzed by transmittance measurement of FT-IR in the spectral region between 3500 cm^-1 and 1300 cm^-1. One of the photoproducts was CO and its formation efficiency was estimated to be approximately 0.6. The photodissociation reaction of HFA is expected to be useful for the actinometer by IR spectroscopy of the photoproduct.

Chemical actinometer for UV laser nanoprocessing has been developed using infrared spectroscopy for the photoproduct of UV irradiated acetylacetone. Sample was hexafluoroacetylacetone, HFA, in which the H atoms of two methyl groups of acetylacetone are replaced by F atoms. It was irradiated by a KrF excimer laser with the oscillation wavelength of 248 nm during 100 seconds and the photoproducts were analyzed by transmittance measurement of FT-IR in the spectral region between 3500 cm^-1 and 1300 cm^-1. One of the photoproducts was CO and its formation efficiency was estimated to be approximately 0.6. The photodissociation reaction of HFA is expected to be useful for the actinometer by IR spectroscopy of the photoproduct.

Synthesis of single-wall carbon nanotubes (SWNTs) was carried out by an ablation method using a XeCl excimer laser with the oscillation wavelength of 308 nm. It was irradiated onto a graphite target containing Co and Ni at the temperatures of 1273 K, 1373 K, 1473 K and 1623 K under the atmosphere (0.1 M Pa) of Ar gas with the flow rate of 12 ml/min. It was found that SWNTs were formed in ablated carbonaceous soot. The diameter distribution and the length were estimated to be 1.2 similar to 1.7 nm and > 2 mu m, respectively, by the measurements of Raman spectrum and images of scanning and transmission electron microscopes. The yield of SWNTs was the highest for the laser ablation at the highest temperature of 1623 K. (c) 2005 Elsevier B.V. All rights reserved.

Photochemistry of Sm3+ has been studied by means of the nanosecond laser flash photolysis using a KrF excimer laser with the oscillation wavelength of 248 nm. Samples were an air-saturated methanol solution Of SmCl3 and that of SmBr3. It is found that the photoreduction of Sm3+ to Sm2+ is induced in the methanol solution of SmCl3 and the photoreduction yield at 100 ns, after the laser irradiation and the lifetime of Sm2+ are estimated to be 0.29 +/- 0.06 and 5.2 +/- 0.7 mu s, respectively. In the photolysis of the methanol solution of SmBr3, a solvated electron, e(sol)(-) and Br-2(-) were formed. (c) 2005 Elsevier B.V. All rights reserved.

Photochemistry of Sm3+ has been studied by means of the nanosecond laser flash photolysis using a KrF excimer laser with the oscillation wavelength of 248 nm. Samples were an air-saturated methanol solution Of SmCl3 and that of SmBr3. It is found that the photoreduction of Sm3+ to Sm2+ is induced in the methanol solution of SmCl3 and the photoreduction yield at 100 ns, after the laser irradiation and the lifetime of Sm2+ are estimated to be 0.29 +/- 0.06 and 5.2 +/- 0.7 mu s, respectively. In the photolysis of the methanol solution of SmBr3, a solvated electron, e(sol)(-) and Br-2(-) were formed. (c) 2005 Elsevier B.V. All rights reserved.

A novel radiation source in the terahertz wave spectral region is being developed. The radiation is produced by electrons, which undergo a half-cyclotron rotation. Injecting the electron bunch with the energy of 150 MeV into the 3 m-long solenoid field, we observed that the radiation had the intense millimeter spectral component when the cyclotron resonant frequency was set to be 4 THz. The numerical calculation revealed that the radiation could be regarded as a half-cycle radiation with the pulsewidth approximately equaled to that of the electron bunch. Also, the calculation pointed out the possibility to amplify such radiation in the optical resonator. (C) 2004 Elsevier B.V. All rights reserved.

A novel radiation source in the terahertz wave spectral region is being developed. The radiation is produced by electrons, which undergo a half-cyclotron rotation. Injecting the electron bunch with the energy of 150 MeV into the 3 m-long solenoid field, we observed that the radiation had the intense millimeter spectral component when the cyclotron resonant frequency was set to be 4 THz. The numerical calculation revealed that the radiation could be regarded as a half-cycle radiation with the pulsewidth approximately equaled to that of the electron bunch. Also, the calculation pointed out the possibility to amplify such radiation in the optical resonator. (C) 2004 Elsevier B.V. All rights reserved.

A prototype of compact Free-Electron Maser (FEM) has been designed for the operation in a usual small laboratory which does not have electric source capacity available enough. The electron energy is 60-120 keV. As it is lower, stronger guiding magnetic field is necessary in addition to wiggler field. To fulfil this condition a solenoid-induced helical, wiggler is applied from the viewpoint of saving the electric power of restricted source capacity. The wiggler, for example, with the period of 12 mm creates the field of 92 G in the guiding field of 3.2 kG. The whole system of FEM has been just constructed in a small-scale laboratory. It is so small to occupy the area of 0.7 x 2.9 m(2). (C) 2003 Elsevier Science B.V. All rights reserved.